Age of informant on death certificate in 1888

[MJW]

I wonder if he could read and check what was written!!

Many adult informants made their mark on their children's briths and parent's deaths and could neither read nor write according to their 1901 & 1911 Irish census (often someone else filled the census in and indicated the head could read, despite them marking X on everything, vanity perhaps). Whether they could read does not affect their ability to provide the info and bear witness in the future if required. Same goes for marriage witnesses, in law there is no age limit stated even today. Some Councils state 16 for their Registry Office ceremonies.
You can register a birth or death today even if cannot "speak or understand English" you are required to bring a friend or interpretor to assist.
https://www.lancashire.gov.uk/births-marriages-and-deaths/births/ Birmingham etc.

Thanks Jon_ni, very interesting.